Progressive induction heating apparatus



June 18, 1946. v. w. SHERMAN 2,402,136

PROGRESSIVE INDUCTION HEATING APPARATUS Filed April 5, 1945 I N V EN TOR. Vf/P/VO/V SHE/W414 Patented Junei, 194$ PROGRESSIVE INDUCTION HEATING APPARATUS Vernon .W. Sherman, Summit, N. 3., assignor to Federal Telephone a Radio Corporation, New York, N. Y., a corporation of Delaware Application April 5, 1943, Serial No. 481,803

9 Claims.

This invention relates to apparatus for the in-. duction heating and hardening of'gear teeth and the like and is specially directed to the production of an improved apparatus designed for the progressive inductive heating of gear teeth and rapid quenching in a suitable cooling medium as required for obtaining a maximum degree of hardening. It is accordingly adapted for inductive heating of the gear teeth in succession or progressively so as to eiTect substantial economies in the energy and power consumption and with the generation of heat in the work surfaces at a higher rate for the given power output while permitting this desirable method of heating and quenching to be effected rapidly and in a continuous process or operation.

The present improvements may desirably employ an induction heating element specially designed to operate with a high degree of heat concentration and rapid rate of heating by the employment of ultra-high frequency currents in the megacycle range. This frequency may desirably be in the order of from 5,000,000 to 15,000,000 cycles from which it is possible to reduce the heat treatment time to a period of one second or less.

The above-described and other features and advantages of the, present improvements will be more fully understood by referenceto the accompanying drawing wherein like reference characters of the description are applied to the corresponding parts in the several views.

In the drawing: Fig. 1 is a view in elevation of the heating and quenching apparatus according to one embodiment of the present invention with a portion broken away. a

Fig. 2 is a central vertical cross-sectionalview taken on line 2-2 of Fig. 1;

Fig. 3 is a partial view thereof in vertical longitudinal section;

Fig. 4 shows a portion of the heating element on an enlarged scale.

In the preferred embodiment of the invention as shown, I indicates a suitable elongated tank to contain the quenching liquid as indicated level of the cooling medium a indicated. The heating element is supported so as to be stationary during the inductive heating operation, and the work-piece to be treated, a gear l as here shown, is rotated and longitudinally advanced with relation thereto so as to successively position its teeth between the inductor tangents 3 and in spaced relation therefrom for inductive heating.

For supporting and advancing the gear to be treated in accordance with the invention, it is detachably fitted to a movable carrier arranged to support the gear within thebath with the major portion thereof immersed in the cooling liquid. It is further designed to effect the rotation of the gear as it is advanced to maintain proper indexing or registration of the teeth with the inductor tangents or active sections in properly spaced relation thereto. To this end, a carriage 5 is formed as shown of connected side plates, provided with grooved rollers 6 journalled on hearing pins 1 to ride on parallel rails 8 positioned at the bottom of the tank. The upper ends of the carriage side plates are formed with end bearing slots 9 to receive a bearing pin i0 fitted to the bearing aperture of the gear whereby it is supported on the carriage for longitudinal movement of the gear, a rack I2 is provided, centrally positioned in the bottom of the tank and extending longitudinally thereof. To effect the required rotational movement of the gear, a rack i2 is provided, centrally positioned in ,the bottom of the tank end extending longitudinally thereof. The rack as shown is formed integral with the guide rails I. Journalled upon a bearing pin it, which is also a connecting pin for the carriage side plates and retained by nut it threaded thereon. is an idler or intermediate gear I 8 meshing at its underside with the stationary rack and at its upper side with the teeth of the port having a gearing shoulder II for supporting the inductor in operating position. The length of the tank and associated rack i2 is such as to extend beyond the co-operative position with the inductor to give clearance at each end thereof for the vertical positioning of the gear 4. within 3 the carriage bearings and to permit easy removal thereof after treatment.

To transmit the required uniform motion to the carrier during the inductive heating operation a suitably driven drive chain 20 is provided carried by driven sprockets 2| and provided with an upwardly extended finger or detent 22; The detent is positioned'to engage co-acting latch or finger 24 pivotally carried by the carriage side plate as shown and adapted to be swung upwardly out of engaging position during periods of assembly of the gear in position and during return shift of its carriage. The sprockets are positioned to effect release of the carriage at the extreme end positions of the movement of the latter for convenience in assembling and removing the gears under treatment.

The rate of speed of the drive chain is governed to determine the duration of exposure of the gear teeth to the inductive heating and the level of the cooling medium in its spaced relation to the inductor. will determine the time interval of quenching which will occur promptly upon completion of the heating operation.

There is accordingly provided an improved apparatus adapted materially to facilitate the progressive heating and quenching of gear teeth and the like by a continuous production method with the interval between the' heating and quenching reduced to a minimum thereby to substantially reduce the heating of internal layers by heat conduction from the surface or current carrying layer of the portion under treatment.

While there is shown an approved embodiment of the features of the invention it will be under-- stood that various modifications may be made therein without departing from the scope of the invention as defined in the claims. Also, while the improved apparatus may be employed as described to elTect the quick quenching of the treated portions after heating it will be appreciated that it may be used to advantage for feeding the gears in proper registration with the inductor without the liquid quenching in instances where the character of heating as related to the sectional area of the gears is such as to have selfquenching hardening action or for purposes of controlled tempering of a previously hardened gear.

What is claimed is:

1. An apparatus for progressive induction heating and quenching of work-pieces of the means for energizing the inductor.

3. An apparatus for induction heating and hardening of the character described comprising in combination with a tank and a quenching medium therein, a longitudinally extending inductor element supported above the quenching medium and in close spaced relation thereto and formed for close coupling registration with the surfaces to be treated, a travelling support for the work rnovable longitudinally of the tank, means for character described comprising in combination I with a tank and a quenching liquid therein, a longitudinally extending inductor element supported above the quenching liquid and in close spaced relation thereto and having active por-- tions formed for close spaced registration with the surfaces to be treated, a traveling support for the work movable within the tank to pass beneath the inductor, means for journalling a work piece for rotative movement on the support in a position partially submerged in the quenching liquid and means to effect rotation of the Work piece as it is progressed along said inductor element in register with the active portions thereof,

and means for energizing the inductor element) journalling a work piece for rotative movement on the support in a position with a portion thereof immersed in the quenching medium and means to efiect rotation of the work piece as it is progressed beneath the inductor consisting of a rack extending parallel to said inductor element and supported within the tank and a pinion journalled in the movable support in mesh with the rack and connected to rotate the work piece as it is progressed along said rack, and means for energizing the inductor element.

4. An apparatus for the inductive heating and quenching of gear teeth comprising an elongated tank and a quenching liquid therein, a longitudinally extending inductor element supported above the quenching liquid in close proximity thereto, a carriage support movable longitudinally of the tank and formed for detachabl supporting a work-piece gear in position to pass beneath theinductor element, means to advance the carriage longitudinally of the tank comprising journalled sprockets, an'endless chain carried thereby to be parallel to the tank, a detent carried by the chain, a co-acting shiftable detent supported on the carriage for engagement with the chain detent, said sprockets being positioned for releasing the carriage engagement at the respective ends of the carriage travel and means for rotating the gear as it is progressed along the inductor element consisting of a rack extendin longitudinally of the tank, a pinion journalled in the carriage to mesh with the rack and with the work piece gear, and means to energize the inductor element.

5. An apparatus for induction heating and hardening of gears and like work pieces comprising a quenching tank and a cooling medium therein, an inductor element of sinuous form supported above the cooling medium and formed for spaced registration into the reentrant portions of the work piece,-a traveling support for the gear movable longitudinally within the tank and having a bearing support to rotate the work piece to position it in spaced registration with the inductor element, a pinion journalled in said support for meshing engagement with the work piece and a longitudinally extending rack supported within the tank in position to be engaged by the pinion torotate the work piece in register with the inductor element during movement thereof longitudinally of the tank and said rack being extendedtforwardly and rearwardly of the inductor element to provide clearance positioning of the work piece at the respective ends of its longitudinal movement, and means for energizawaits portion thereof immersed in the quenching medium and means to effect rotation of the work piece as it is progressed in a horizontal direction beneath the inductor consisting of a longitudinal rack extending in said direction and supported within the tank, and a pinion journaled in the movable support in mesh with the-rack and connected to rotate the work piece as it is progressed along said rack, means for energizing the inductor element and said inductor element being supported to be shiftable from operative position.

. 7. An apparatus ior induction heating and hardening of the character described comprising in combination with a tank and a quenching medium therein, a longitudinally extending inductor element supported above the quenching medium and in close proximity thereto and formed for spaced registration with the surfaces to be treated, a traveling support for the work piece movable in a horizontal direction within the tank, means for supporting a work piece detachably on the support. for rotatlve movement about a horizontal axis and means to 'eflect rotation of the work. piece as it is progressed in a horizontal direction perpendicular to said axis in the tank consisting of a rack supported within the tank and a pinion journalled in the movable support in mesh with the rack and connected to rotate the work piece, and means for energizing the inductor element with a high frequency current.

8. In an apparatus for progressive induction heating of work pieces of the character described comprising a longitudinally extending inductor element having portions formed for close spaced registration with the surfaces to be treated, a traveling support for the work movable to pass beneath the inductor, means for journalling a work piece for rotative movement on the support and'means to effect simultaneous rotation and progression of the work piece along the inductor element in register with the active portions thereof.

9. In an apparatus for induction heating of toothed wheels and the like comprising a longitudinally extending inductor element having active portions formed for close-spaced registration with the re-entrant portions of the toothed wheel, a traveling support for the toothed wheel the rack and connected to rotate the toothed wheel.

VERNON W. SHERMAN. 

